The present disclosure includes a computing device comprising one or more processors, a non-transitory machine-readable medium storing a program executable by the one or more processors, the program comprising sets of instructions for: receiving an audio signal from a microphone on the computing device, receiving the audio signal from an external device coupled to the computing device, and cancelling, by the computing device, noise in the audio signal.

Adaptive filters output a cancellation sound from a speaker, a selector selects outputs of a plurality of auxiliary filters each corresponding to different positions, a subtractor subtracts the selected output from the output of the microphone and outputs the subtracted output to the adaptive filter as an error signal, and a position detection device detects a position of a head of a user. A transfer function estimated so that the error signal becomes 0 when noise is canceled at the corresponding position is preset in the auxiliary filter. When the auxiliary filter corresponding to the position close to the head of the user changes, the switching control unit stepwise increases the frequency with which the output of the auxiliary filter is selected by the selector to 100%.

A noise reduction system (2) and a method for actively compensating background noises in a passenger transport area of a vehicle. Said system includes a control unit (8), at least one microphone (10), at least one sound generator (12) and a position detection unit for detecting a position and/or orientation of the head (16) of a user. The control unit (8) is coupled to the position detection unit on an input side, is configured to receive position data and to determine a position signal from the position data, and to generate an antinoise signal from the background noise signal and the position signal. The sound generator (12) is configured to generate antinoise from the antinoise signal such that, by superimposing the antinoise in a quiet zone (20a, 20b) within the passenger transport area, which antinoise is in phase opposition with the background noise, active reduction of the background noise is achieved. The position detection unit is a 3D camera arrangement (14).

A system for controlling an engine tone by an artificial intelligence based on a sound quality index of a vehicle may include a sound output device for generating a reinforcing sound to reinforce an engine sound of the vehicle; an engine characteristic measurement sensor for measuring sound source characteristics of the engine sound; an interior noise measurement sensor for detecting interior noise of the vehicle; a signal processing controller that receives signals from the engine characteristic measurement sensor in real time and controls the sound output device such that the engine sound reaches a target tone; and a tone control operation unit connected to the signal processing controller to optimize the sound quality index such that the engine sound reaches the target tone through the artificial intelligence.

A fan control system applied to N fans inside a computer system is disclosed, comprising: a main microphone, a control circuitry, a wave generation circuitry and a number N of fan controllers. The control circuitry calculates a basic frequency value according to a temperature inside the computer system, and continuously updates a parameter by any known optimization algorithm according to a main audio signal from the main microphone. The wave generation circuitry generates N square waves according to the basic frequency value and the parameter. The N fan controllers respectively form and transmit N modulation signals to the N fans according to the N square waves and N tachometric signals from the N fans. The parameter is one of a frequency variation and a set of phase differences, and the N square waves have the same frequency.

A noise reduction system (2) and a method for actively compensating background noises in a passenger transport area of a vehicle. Said system includes a control unit (8), at least one microphone (10), at least one sound generator (12) and a position detection unit for detecting a position and/or orientation of the head (16) of a user. The control unit (8) is coupled to the position detection unit on an input side, is configured to receive position data and to determine a position signal from the position data, and to generate an antinoise signal from the background noise signal and the position signal. The sound generator (12) is configured to generate antinoise from the antinoise signal such that, by superimposing the antinoise in a quiet zone (20a, 20b) within the passenger transport area, which antinoise is in phase opposition with the background noise, active reduction of the background noise is achieved. The position detection unit is a 3D camera arrangement (14).

An earphone controlling method includes: acquiring a first sound signal through a bone conduction element of the earphone; determining whether the first sound signal includes a voice signal sent by a wearer of the earphone according to the first sound signal; and controlling the earphone to operate in a transparent transmission mode when the first sound signal includes the voice signal.

A hearing protection and situational awareness system includes a wearable device, speakers, one or more beamformers, a microphone array, and a computation unit. The system generates a three-dimensional (3D) binaural sound for enhanced situational awareness; provides hearing protection by active noise cancelation; provides hearing enhancement by automatic gain control; and performs background noise reduction and cancelation. The system performs automated sound detection, identification, and localization, with automated voice assistance, and facilitates clear two-way communications. Each beamformer(s) outputs a sound track associated with a sound captured by the microphone array in a direction(s) of an acoustic beam pattern(s). The computation unit combines filtered sound tracks generated using head-related transfer function (HRTF) filters into left and right sound channels to drive the speaker(s) in left and right hearing members of the wearable device, respectively, thereby generating a 3D binaural sound including cues of the sound source directions.

Noises that are to be emitted by an aerial vehicle during operations may be predicted using one or more machine learning systems, algorithms or techniques. Anti-noises having equal or similar intensities and equal but out-of-phase frequencies may be identified and generated based on the predicted noises, thereby reducing or eliminating the net effect of the noises. The machine learning systems, algorithms or techniques used to predict such noises may be trained using emitted sound pressure levels observed during prior operations of aerial vehicles, as well as environmental conditions, operational characteristics of the aerial vehicles or locations of the aerial vehicles during such prior operations. Anti-noises may be identified and generated based on an overall sound profile of the aerial vehicle, or on individual sounds emitted by the aerial vehicle by discrete sources.

An audio processing system, such as an active noise cancellation system, and method suppresses tonal howling in a feedback system based on a gain enhancement system that emphasizes the howling signal and deemphasizes non-howling signals. The howling signal is extracted from an error signal generated from sound from a speaker sensed by an error sensor. The gain enhancement signal is generated based on a first power ratio between a filtered reference signal, generated based on sound sensed from external noise by a reference sensor, and a filtered error signal and/or a second power ratio between two filtered error signals with different passbands. Using the gain enhancement signal and the howling signal, a howling suppression gain signal is generated and used to amplify the error signal. A feedback signal produced based on the amplified error signal is provided to the speaker as an anti-noise signal with suppressed howling.